Indazole compounds, and their production and use

ABSTRACT

A compound of the formula: ##STR1## wherein R is a C 1  -C 5  alkyl group, a C 3  -C 4  alkenyl group, a C 3  -C 4  alkynyl group or a C 1  -C 3  alkoxy(C 1  -C 2 )alkyl group, which is useful as a herbicide.

This application is a divisional of copending application Ser. No.008,314, filed on Jan 29, 1987.

The present invention relates to indazole compounds, and theirproduction and use. More particularly, it relates to novel indazolecompounds, a process for producing them, and their use as herbicides.

Some tetrahydro-2H-indazole derivatives are known to be effective asherbicides (U.S. Pat. No. 4,059,434). However, their herbicidal activityis not sufficiently high. Further, their selectivity between crop plantsand undesired weeds is inferior. Thus, they are not always satisfactoryfor current use.

It has now been found that the indazole compounds of the formula:##STR2## wherein R is a C₁ -C₅ alkyl group, a C₃ -C₄ alkenyl group, a C₃-C₄ alkynyl group or a C₁ -C₃ alkoxy(C₁ -C₂)alkyl group show a highherbicidal activity against a wide variety of weeds includingbroad-leaved weeds, Graminaceous weeds, Commelinaceous weeds andCyperaceous weeds in agricultural plowed field by foliar or soiltreatment without producing any material phytotoxicity on variousagricultural crops such as corn, sorghum, wheat, barley, rice plant,syybean, peanut and cotton. Examples of the broad-leaved weeds are wildbuckwheat (Polygonum convolvulus), pale smartweed (Polygonumlapathifolium), common purslane (Portulaca oleracea), common chickweed(Stellaria media), common lambsquarters (Chenopodium album), redrootpigweed (Amaranthus retroflexus), radish (Raphanus sativus), wildmustard (Sinapis arvensis), shepherdspurse (Capsella bursa-pastoris),hemp sesbania (Sesbania exaltata), sicklepod (Cassia obtusifolia),velvetleaf (Abutilon theophrasti), prickly sida (Sida spinosa), fieldpansy (Viola arvensis), catchweed bedstraw (Galium aparine), tallmorningglory (Ipomoea purpurea), field bindweed (Convolvulus arvensis),jimsonweed (Datura stramonium), black nightshade (Solanum nigrum),persian speedwell (Veronica persica), common cocklebur (Xanthiumpensylvanicum), common sunflower (Helianthus annuus), scentlesschamomile (Matricaria perforata), corn marigold (Chrysanthemum segetum),sun spurge (Euphorbia helioscopia), etc. Examples of Graminaceous weedsare Japanese millet (Echinochloa frumentacea), barnyardgrass(Echinochloa crus-galli), green foxtail (Setaria viridis), largecrabgrass (Digitaria sanguinalis), annual bluegrass (Poa annua),blackgrass (Alopecurus myosuroides), oats (Avena sativa), wild oats(Avena fatua), johnsongrass (Sorghum halepense ), quackgrass (Agropyronrepens), downy brome (Bromus tectorum), etc. Examples of Commelinaceousweeds are asiatic dayflower (Commelina communis), etc. Examples of theCyperaceous weeds are rice flatsedge (Cyperus iria), yellow nutsedge(Cyperus esculentus) etc.

It is especially notable that some of the indazole compounds (I) exert aprominent herbicidal activity by soil application before or aftergermination of undesired weeds in the paddy field without any materialphytotoxicity. For instance, they show a high herbicidal potency onbroad-leaved weeds such as common falsepimpernel (Lindernia procumbens),indian toothcup (Rotala indica) and waterwort (Elatine triandra),Graminaceous weeds such as barnyardgrass (Echinochloa oryzicola),Cyperaceous weeds such as Sm.fl. umbrella sedge (Cyperus difformis),hardstem bulrush (Scirpur juncoides) and needle spikerush (Eleocharisacicularis) and others such as monochoria (Monochoria vaginalis) andarrowhead (Sagittaria pygmaea) without producing any materialphytotoxicity to rice plants on flooding treatment.

Among the indazole compounds (I), preferred are those wherein R is a C₂-C₄ alkyl group, a C₃ -C₄ alkenyl group, a C₃ -C₄ alkynyl group or a C₁-C₃ alkoxymethyl group. The most preferred are3-chloro-2-[6-fluoro-3-(2-propynyl)-C2H-benzothiazolon-5-yl]-4,5,6,7-tetrahydro-2H-indazole,3-chloro-2-(6-fluoro-3-isopropyl-2H-benzothiazolon-5-yl)-4,5,6,7-tetrahydro-2H-indazole, etc.

The indazole compound (I) is obtainable by reacting3-chloro-2-[6-fluoro-2(3H)-benzothiazolon-5-yl]-4,5,6,7-tetrahydro-2H-indazoleof the formula: ##STR3## with an R-introducing agent of the formula:

    R--X                                                       (III)

wherein X is a leaving group such as a halogen atom (e.g. chlorine,bromine or iodine) and R is as defined above.

The reaction is usually carried out in an inert solvent in the presenceof an acid eliminating agent at a temperature of 0° to 80° C. for aperiod of 1 to 24 hours. The amounts of the R-introducing agent (III)and the acid eliminating agent may be respectively 1 to 3 equivalentsand 1 to 3 equivalents to one equivalent of the starting compound (II).

Examples of the inert solvent include aromatic hydrocarbons (e.g.benzene, toluene, xylene), nitriles (e.g. acetonitrile,isobutylonitrile), acid amides (e.g. formamide, N,N-dimethylformamide,N,N-dimethylacetamide), dimethylsulfoxide, water, and a mixture thereof.As the acid eliminating agent, there may be exemplified an inorganicbase (e.g. sodium hydroxide, potassium hydroxide, potassium carbonate,sodium hydride), etc.

After completion of the reaction, the reaction mixture is subjected toordinary post-treatment such as dilution with water, extraction with anorganic solvent and concentration. If desired, any conventionalpurification procedure such as chromatography and recrystallization maybe adopted.

The indazole compound (I) is also obtainable by reacting ahexahydroindazolone compound of the formula: ##STR4## wherein R is asdefined above (available in a tautomeric mixture form) with achlorinating agent.

The reaction is usually accomplished in an inert solvent at atemperature of 60° to 200° C., preferably of 100° to 180° C., under anormal pressure or an elevated pressure. The chlorinating agent may beused in an amount of 1 to 4 equivalents to one equivalent of thestarting compound (IV).

Examples of the chlorinating agent are phosgene, trichloromethylchloroformate, oxalyl chloride, etc. As the inert solvent, there may beexemplified aromatic hydrocarbons (e.g. chlorobenzene, toluene, xylene),halogenated hydrocarbons (e.g. 1,2-dichloroethane,1,1,1-trichloroethane), etc.

After completion of the reaction, excess of the chlorinating agent aswell as the solvent are removed. If desired, the residue may be purifiedby chromatography or recrystallization.

Typical examples of the indazole compounds (I) which can be produced bythe above procedures are shown in Table 1.

                  TABLE 1                                                         ______________________________________                                         ##STR5##                      (I)                                                      R                                                                   ______________________________________                                                  CH.sub.3                                                                      C.sub.2 H.sub.5                                                               n-C.sub.3 H.sub.7                                                             i-C.sub.3 H.sub.7                                                             n-C.sub.4 H.sub.9                                                             i-C.sub.4 H.sub.9                                                             sec-C.sub.4 H.sub.9                                                           sec-C.sub.5 H.sub.11                                                          n-C.sub.5 H.sub.11                                                            i-C.sub.5 H.sub.11                                                            CH.sub.2CHCH.sub.2                                                            CH.sub.3 CHCHCH.sub.2                                                         CHCCH.sub.2                                                                   CH.sub.3 CCCH.sub.2                                                           CH.sub.3 OCH.sub.2                                                            C.sub.2 H.sub.5 OCH.sub.2                                                     n-C.sub.3 H.sub.7 OCH.sub.2                                         ______________________________________                                    

Practical and presently preferred embodiments for production of theindazole compounds (I) are illustratively shown in the followingexamples.

EXAMPLE 1

A suspension of sodium hydride (60% oil; 50 mg) in N,N-dimethylformamide(3 ml) was cooled to 0° C., and3-chloro-2-(6-fluoro-2(3H)-benzothiazolon-5-yl)-4,5,6,7-tetrahydro-2H-indazole(390 mg) was added thereto at 0°, followed by stirring at the sametemperature for 30 minutes. To the suspension, propargyl bromide (160mg) was added, and the resultant mixture was heated to a temperature of50° to 60° C. and allowed to react at the same temperature for 2 to 3hours. Water was added to the reaction mixture, which was extracted withethyl acetate. The extract was washed with water, dried andconcentrated. The residue was purified by silica gel thin layerchromatography using a mixture of ethyl acetate and hexane (1:4) as adeveloping solvent to give3-chloro-2-[6-fluoro-3-(2-propynyl)-2H-benzothiazolon-5-yl]-4,5,6,7-tetrahydro-2H-indazole(24.1 gg). m.p., 130°-132° C.

EXAMPLE 2

2-(6-Fluoro-3-sec-butylbenzothiazolon-5-yl)-3,3',4,5,6,7,-hexahydro-2H-indazol-3-one(9.37 g), toluene (20 ml), 1,2-dichloroethane (30 ml) andtrichloromethylchlorofommate (5.2 ml) were charged in an autoclave madeof Harstelloy, and the resultant mixture was allowed to react at atemperature of 120° to 130° C. for 3 hours under pressure. Aftercooling, the reaction mixture was concentrated under reduced pressure,and the residue was purified by silica gel column chromatography using amixture of hexane and ethyl acetate as an eluent to give3-chloro-2-(6-fluoro-3-sec-butyl-2H-benzothiazolon-5-yl)-4,5,6,7-tetrahydro-2H-indazole(3.88 g). n_(D) ²².5 1.5713.

In the same manner as above, the indazole compounds (I) as shown inTable 2 were obtained.

                  TABLE 2                                                         ______________________________________                                         ##STR6##                      (I)                                            Compound                                                                      No.        R              Physical property                                   ______________________________________                                        1          C.sub.2 H.sub.5                                                                              resinous                                            2          n-C.sub.3 H.sub.7                                                                            n.sub.D.sup.25.0 1.5908                             3          CH.sub.2CHCH.sub.2                                                                           resinous                                            4          CHCCH.sub.2    m.p. 130-132° C.                             5          CH.sub.3 OCH.sub.2                                                                           m.p. 141-142° C.                             6          iso-C.sub.3 H.sub.7                                                                          resinous                                            7          sec-C.sub.4 H.sub.9                                                                          n.sub.D.sup.22.5 1.5713                             8          (C.sub.2 H.sub.5).sub.2 CH                                                                   n.sub.D.sup.23.5 1.5763                             ______________________________________                                    

The starting compounds (II) and (Iv) can be produced respectivelyaccording to Routes (A) and (B) as shown below: ##STR7## wherein R is asdefined above.

Route A

Step (1):

2-Fluoro-5-nitrophenylhydrazine (V) is reacted with a2-cyclohexanonecarboxylic ester of the formula: ##STR8## wherein Y is C₁-C₈ alkyl to give2-(2-fluoro-5-nitro-phenyl)-1,2,4,5,6,7-hexahydro-3H-indazole (in atautomeric mixture form) (VII).

The reaction is accomplished at a temperature of 20° to 120° C. for aperiod of 1 to 24 hours in an inert solvent such as a lower aliphaticcarboxylic acid (e.g. acetic acid, propionic acid). The compound (VI)may be used in an amount of to 1.5 equivalents to the compound (V).

After completion of the reaction, the reaction mixture is poured intoice-water, and the precipitated crystals are collected by filtration. Ifnecessary, any conventional purification procedure such asrecrystallization or chromatography may be applied.

The starting compound (V) can be produced from 2-fluoro-5-nitroanilineby the method as described in [J. Chem. Soc., (C), 1970, 2106].

Step (2):

2-(2-Fluoro-5-nitrophenyl)-1,2,4,5,6,7-hexahydro-3H-indazole (VII) isreacted with a chlorinating agent, if necessary, in the presence of adehydrohalogenating agent to give3-chloro-2-(2-fluoro-5-nitrophenyl)-4,5,6,7-tetrahydro-2H-indazole(VIII).

The reaction is carried out in an inert solvent at a temperature of 20°to 200° C., preferably of 80° to 130° C., under a pressure of normalpressure to 50 kg/cm² for a period of 1 to 240 hours. As thechlorinating agent, there are exemplified phosgene, oxalyl chloride,trichloromethyl chloroformate, phosphorus oxychloride, thionyl chloride,etc. Examples of the dehydrochlorinating agent are an organic base (e.g.pyridine, triethylamine, N,N-diethylaniline), etc. Further, thechlorinating gent and the dehydrochlorinating agent may be respectivelyused in amounts of 1 to 15 equivalents and of a catalytic amount to 1equivalent to one equivalent of the compound (VII).

As the solvent, there may be employed, for instance, aliphatichydrocarbons (e.g. hexane, ligroin), aromatic hydrocarbons (e.g.toluene, benzene, xylene), halogenated hydrocarbons (e.g. chloroform,carbon tetrachloriee, dichloroethane, tetrachloroethane, chlorobenzene,dichlorobenzene), ethers (e.g. diisopropyl ether, dioxane, ethyleneglycol dimethyl ether), tertiary amines (e.g. pyridine, triethylamine,N,N-dimethylmorpholine), or their mixtures.

After completion of the reaction, the reaction mixture is subjected toordinary post-treatment such as concentration. If necessary, anyconventional purification procedure such as recrystallization orchromatography may be applied.

Step (3):

3-Chloro-2-(2-fluoro-5-nitrophenyl)-4,5,6,7-tetrahydro-2H-indazole(VII)) is reacted with a reducing agent to give2-(5-amino-2-fluorophenyl-3-chloro-4,5,6,7-tetrahydro-2H-indazole (IX).

The reaction is usually carried out by treatment of the compound (VIII)with a reducing agent in an inert solvent at a temperature of 60° to120° C. for a period of 1 to 24 hours.

As the reducing agent, there may be used iron powder, zinc powder, tinpowder, ferrous chloride, zinc chloride, stannous chloride, etc.Examples of the inert solvent are aqueous solutions of acetic acid,hydrochloric acid, sulfuric acid, etc. If necessary, any organic solventsuch as ethyl acetate may be present in the reaction system. The amountof the reducing agent is usually from 3 to 30 equivalents, preferablyfrom 5 to 20 equivalents, to one equivalent of the compound (VIII).

After completion of the reaction, the residue is removed by filtration,and the filtrate is extracted with an organic solvent. The extract iswashed with water or an aqueous solution of sodium bicarbonate andsubjected to concentration. When desired, any conventional purificationmethod, e.g. recrystallization or chromatography, may be also applied.

Step (4):

2-(5-Amino-2-fluorophenyl)-3-chloro-4,5,6,7-tetrahydro-2H-indazole (IX)is reacted with a thiocyanate and then with a halogen to give2-(2-amino-6-fluorobenzothiazol-5-yl)-3-chloro-4,5,6,7-tetrahydro-2H-indazole(X).

The reaction is normally carried out in an inert solvent at atemperature of 0° to 50° C. for a period of 1 to 100 hours.

Examples of the thiocaanate are sodum thiocyanate, potassiumthiocyanate, ammonium thiocyanate, etc. As the halogen, there may beused bromine, chlorine, etc. The inert solvent is, for instance, aqueousacetic acid, aqueous hydrochloric acid, aqueous sulfuric acid, etc.Usually, the thiocyanate and the halogen are respectively used in 1 to10 equivalents and 1 to 10 equivalents to one equivalent of the compound(IX).

After completion of the reaction, the reaction mixture is neutralizedand the precipitated crystals are collected by filtration and air-dried.If necessary, any conventional purification method such asrecrystallization and chromatography may be applied.

Step (5):

2-(2-Amino-6-fluorobenzothiazol-5-yl)-3-chloro-4,5,6,7-tetrahydro-2H-indazole(X) is subjected to diazotiation, followed by decomposition of theresulting diazonium salt to give3-chloro-2-[6-fluoro-2(3H-benzothiazolon-5-yl]-4,5,6,7-tetrahydro-2H-indazole(II).

The diazotiation is carried out by reacting the compound (X) with adiazotiating agent ordinarily in an inert solvent (e.g. aqueous sulfuricacid, aqueous hydrochloric acid) at a temperature of -5° to 5° C. for aperiod of 0.5 to 24 hours, and the decomposition of the resultingdiazonium salt is effected normally by heating at a temperature of 70°to 100° C. for a period of 0.5 to 24 hours. As the diazotiating agent,there may be employed an alkali metal nitrite such as sodium nitrite orpotassium nitrite. The amount of the diazotiating agent is usually from1 to 2 equivalents to the compound (X).

After completion of the reaction, the reaction mixture is diluted withwater and extracted with an organic solvent, followed by conventionalpost-treatment such as washing with water, drying and concentration. Ifnecessary, any purification method such as chromatography may be

The compounds (VII), (VIII), (IX) and (X) as produced in the above RouteA are novel and can be covered by the general formula: ##STR9## whereinA is ##STR10## and Q is --C(═O)-- or --C(Cl)═ but when Q is -C(═O), A is##STR11##

Practical examples of the conversions in the above Route (A) areillustratively shown below.

EXAMPLE 3

A solution of 2-fluoro-5-nitrophenylhydrazine (53.95 g) in ethyl2-cyclohexanonecarboxylate (53.65 g) was heated under reflux for 4hours. After cooling, the reaction mixture was poured into ice-water.The precipitated crystals were collected by filtration, washed withwater add hexane and dried to obtain2-(2-fluoro-5-nitrophenyl)-1,2,4,5,6,7-hexahydro-3H-indazol-3-one. m.p.,220.0° C.

EXAMPLE 4

To a solution of2-(2-fluoro-5-nitrophenyl)-1,2,4,5,6,7-hexahydro-3H-indazol-3-one (66.87g) in toluene (125 ml) and 1,2-dichloroethane (175 ml), there was addedtrichloromethyl chloroformate (71.57 g), and the resultant mixture wasallowed to react in an autoclave at a temperature of 120° to 130° C.under a pressure of 25 kg/cm² for 3 hours. After cooling, the solventwas removed by distillation. The residue was purified by silica gelcolumn chromatography using a mixture of ethyl acetate and n-hexane(1:6) as an eluent to give3chloro-2-(2-fluoro-5-nitrophenyl)-4,5,6,7-tetrahydro-2H-indazole. m.p.109.1° C.

EXAMPLE 5

To a suspension of iron powder (28.75 g) in 5 % aqueous acetic acid(57.5 ml) heated at 80° C., a solution of3-chloro-2-(2-fluoro-5-nitrophenyl)-4,5,6,7-tetrahydro-2H-indazole(30.45 g) in acetic acid (103 ml) and ethyl acetate (103 ml) was added,and the resultant mixture was heated at a temperature of 60° to 80° C.under reflux for 3 hours. After cooling, water and ethyl acetate wereadded to the reaction mixture. The residue was removed by filtration.The filtrate was extracted with ethyl acetate, and the extract waswashed with water and an aqueous sodium bicarbonate solution, dried andconcentrated to give2-(5-amino-2-fluorophenyl)-3-chloro-4,5,6,7-tetrahydro-2H-indazole(22.97 g). m.p., 120.9° C.

EXAMPLE 6

2-(5-Amino-2-fluorophenyl)-3-chloro-4,5,6,7-tetrahydro-2H-indazole(22.97 g) was dissolved in 95% aqueous acetic acid (79.53 g), andammonium thiocyanate (15.92 g) was added thereto at room temperature(ca. 20° C.). To the resultant mixture, a solution of bromine (15.89 g)in, acetic acid (23.77 g) was dropwise added in 105 minutes. After beingallowed to stand overnight, the mixture was heated to 100° C., and hotwater (173 ml) was added thereto, followed by filtration. The filtratewas cooled and neutralized with sodium carbonate. The precipitatedcrystals were collected by filtration and dried to give2-(2-amino-6-fluorobenzothiaol-5-yl)-3-chloro-4,5,6,7-tetrahydro-2H-indazole(8.77 g). m.p., 212.4° C.

EXAMPLE 7

A suspension of3-chloro-2-(2-amino-6-fluorobenzothiazol-5-yl)-4,5,6,7-tetrahydro-2H-indazole(8.77 g) in 50% sulfuric acid (68 ml) was cooled to a temperature of 0°to 5° C., and a saturated aqueous solution of sodium nitrite (2.43 g)was dropwise added thereto at the same temperature, followed by stirringat the same temperature for 20 minutes. The diazonium salt solution thusobtained was dropwise added to a mixture of water (23 ml) and conc.sulfuric acid (34 ml) heated at 90° C. and allowed to react at 80° to100° C. for 30 minunites. After cooling, the reaction mixture wascombined with water and extracted with ethyl acetate, washed with water,dried and concentrated to give3-chloro-2-[6-fluoro-2(3H)-benzothiazolon-5-yl]-4,5,6,7-tetrahydro-2H-indazole(0.39 g).

₁ H NMR δ (CDCl₃): 1.5-2.1 (br, 4H), 2.2-3.0 (br, 4H), 6.0-6.9 (br, 1H),7.19 (d, 1H, J=9.0 Hz), 7.20 (d, 1H, J=6.0 Hz).

Route B

Step (6):

The aminobenzothiazolone (XII) is diazotiated to the diazonium salt, andthen the latter is reduced with stannous chloride to give thehydrazinobenzthiazolone (XIII).

For the diazotiation, the aminobenzothiazolone (XII) is reacted with analkali metal nitrite (e.g. sodium nitrite, potassium nitrite) usually inan amount of 1 to 1.2 equivalents in the presence of large excess of anacid (e.g. hydrochloric acid, sulfuric acid) at a temperature of -5° to0° C.

After removal of the remaining nitrite ion, the produced diazonium saltis reduced with stannous chloride in an amount of 3 to 5 equivalents ata temperature of -40° to 0° C. to give the hydrazinobenzthiazolone(XIII) in a salt form. Neutralization of the salt at a temperature below10° C., followed by extraction with an organic solvent and concentrationof the extract gives the hydrazinobenzthiazolone (XIII). When desired,the product may be purified by chromatography.

Step (7):

The hydrazinobenzthiazolone (XIII) is reacted with acyclohexanonecarboxylic ester (VI) to give the hexahydroindazolone (in atautomeric mixture form) (IV).

This reaction is carried out at a temperature of 20° to 120° C. in aninert solvent (e.g. acetic acid. propionic acid). The amount of thecyclohexanonecarboxylic ester (VI) is usually from 1 to 1.1 equivalentsto the compound (XIII).

The reaction mixture is poured into water and subjected to ordinarypost-treatment such as extraction with an organic solvent andconcentration. If necessary, any purification procedure such aschromatography and recrystallization may be applied.

The compounds (XIII) and (IV) as produced in the above Route B are noveland can be covered by the general formula: ##STR12## wherein B is--NHNH₂ or ##STR13## and R is as defined above.

Practical embodiments of the conversions in Route B are shown in thefollowing Examples.

EXAMPLE 8

5-Amino-6-fluoro-3-sec-butylbenzothiazolone (22.95 g) was combined withconc. hydrochloric acid (300 ml), and the resultant mixture was stirredat room temperature for 30 minutes. After cooling to a temperature of-5° to 5° C., a solution of sodium nitrite (6.89 g) in water (30 ml) wasdropwise added thereto, followed by stirring for 30 minutes. Thereaction mixture was cooled to -30° C., and a solution of stannouschloride (36.2 g) in hydrochloric acid (82 ml) was added thereto,followed by stirring at -10° to 0° C. for 2 hours. The insolublematerial was collected by filtration, dissolved in water, neutralizedand extracted with ethyl acetate. The extract was dried and concentratedto give 5-hydrozino-6-fluoro-3-sec-butylbenzothiazolone (13.19 g) as aglassy substance.

In the same manner as above, the compounds (XII) as shown in Table 3were obtained.

                  TABLE 3                                                         ______________________________________                                         ##STR14##                   (XIII)                                           R                   Physical property                                         ______________________________________                                        iso-C.sub.3 H.sub.7 m.p.  66° C.                                       CH.sub.2 CHCH.sub.2 m.p. 130° C.                                       CH.sub.2 CCH        m.p. 163-164° C.                                   ______________________________________                                    

EXAMPLE 9

A mixture of 5-hydrazino-6-fluoro-3-sec-butylbenzothiazolone (6 g) and2-ethoxycarbonylcyclohexanone (4 g) in acetic acid (23.5 ml) wasrefluxed for 2.5 hours. After cooling, water was added to the reactionmixture, which was extracted with ethyl acetate, washed with water,dried and concentrated to give2-(6-fluoro-3-sec-butylbenzothiazolon-5-yl)-3,3',4,5,6,7-hexahydro-2H-indazol-3-one(10.36 g). n_(D) ²².5 1.5736.

In the same manner as above, the compounds (IV) as shown in Table 4 wereobtained:

                  TABLE 4                                                         ______________________________________                                         ##STR15##                    (IV)                                            R                   Physical property                                         ______________________________________                                        iso-C.sub.3 H.sub.7 glassy                                                    CH.sub.2 CHCH.sub.2 m.p. 178-179° C.                                   CH.sub.2 CCH        m.p. 237-237.5° C.                                 ______________________________________                                    

On the practical usage of the indazole compounds (I), they may beapplied in conventional preparation forms such as emulsifiableconcentrates, wettable powders, suspensions and granules in combinationwith conventional solid or liquid carriers or diluents as well assurface active agents or auxiliary agents. The content of the indazolecompounds (I) as the active ingredient in such preparation forms isusually within a range of 0.01 to 90% by weight, preferably of 0.02 to80% by weight. Examples of the solid carrier or diluent are fine powdersor granules of kaolin clay, attapulgite clay, bentonite, terra alba,pyrophyllite, talc, diatomaceous earth, calcite, walnut powders, urea,ammonium sulfate and synthetic hydrous silicate, etc. As the liquidcarrier or diluent, there may be exemplified aromatic hydrocarbons (e.g.xylene, methylnaphthalene), alcohols (e.g. isopropanol, ethylene glycol,cellosolve), ketones (e.g. acetone, cyclohexanone, isophorone), soybeanoil, cotton seed oil, dimethylsulfoxide, N,N-dimethylformamide,acetonitrile, water, etc.

The surface active agent used for emulsification, dispersion orspreading may be any of the anionic and non-ionic type of agents.Examples of the surface active agent include alkylsulfates,alkylarylsulfonates, dialkylsulfosuccinates, phosphates ofpolyoxyethylenealkylaryl ethers, polyoxyethylene alkyl ethers,polyoxyethylene alkylaryl ethers, polyoxyethylene polyoxypropylene blockcopolymer, sorbitan fatty acid esters, polyoxyethylene sorbitan fattyacid esters, etc. Examples of the auxiliary agents includeligninsulfonates, sodium alginate, polyvinyl alcohol, gum arabic, CMC(carboxymethyl cellulose), PAP (isopropyl acid phosphate), etc.

Practical embodiments of the herbicidal composition according to theinvention are illustratively shown in the following examples whereinparts are by weight. The compound number of the active ingredientcorresponds to the one in Table 2.

FORMULATION EXAMPLE 1

Fifty parts of Compound No. 4, 3 parts of calcium ligninsulfonate, 2parts of sodium laurylsulfate and 45 parts of synthetic hydrous silicaare well mixed while being powdered to obtain a wettable powder.

FORMULATION EXAMPLE 2

Five parts of Compound No. 2, 14 parts of polyoxyethylenestyrylphenylether, 6 parts of calcium dodecylbenzenesulfonate, 30 parts of xyleneand 45 parts of cyclohexanone are well mixed to obtain an emulsifiableconcentrate.

FORMULATION EXAMPLE 3

Two parts of Compound No. 5, 1 part of synthetic hydrous silica, 2 partsof calcium ligninsulfonate, 30 parts of bentonite and 65 parts of kaolinclay are well mixed while being powdered. The mixture is then kneadedwith water, granulated and dried to obtain granules.

FORMULATION EXAMPLE 4

Twenty-five parts of Compound No. 4 is mixed with 3 parts ofpolyoxyethylenesorbitan monooleate, 3 parts of carboxymethyl celluloseand 69 parts of water and pulverized until the particle size of themixture becomes less than 5 microns to obtain a suspension.

FORMULATION EXAMPLE 5

Five parts of Compound No. 3, 4 or 5, 14 parts ofpolyoxyethylenestyrylphenyl ether, 6 parts of calciumdodecylbenzenesulfonate, 30 parts of xylene and 45 parts ofN,N-dimethylformamide are well mixed to obtain an emulsifiableconcentrate.

The indazole compounds (I) thus formulated in any suitable formulationform are useful for the pre-emergence or post-emergence control ofundesired weeds by soil or foliar treatment as well as flood followingtreatment. These treatments include the application to the soil surfaceprior to or after the transplanting or the incorporation into the soil.The foliar treatment may be effected by spraying the herbicidalcomposition containing the indazole compounds (I) over the top of theplants. It may also be applied directly to the weeds if care is taken tokeep the chemical off the crop foliage.

The indazole compounds (I) of the invention may be used together withother herbicides to improve their activity as herbicides, and in somecases, a synergistic effect can be expected. Further, they may beapplied in combination with insecticides, acaricidss, nematocides,fungicides, plant growth regulators, fertilzzers, soil improvers, etc.

Furthermore, the indazole compounds (I) can be used as herbicidesapplicable to agricultural plowed field as well as paddy field. They arealso useful as herbicides to be employed for orchard, pasture land,lawn, forest, non-agricultural field, etc.

The dosage rate of the indazole compounds (I) may vary on prevailingweather conditions, formulation used, prevailing season, mode ofapplication, soil involved, crop and weed species, etc. Generally,however, the dosage rate is from 0.02 to 100 grams, preferably from 0.04to 50 grams, of the active ingredient per are. The herbicidalcomposition of the invention formulated in the form of an emulsifiableconcentrate, a wettable powder or a suspension may ordinarily beemployed by diluting it with water at a volume of 1 to 10 liters perare, if necessary, with addition of an auxiliary agent such as aspreading agent. Examples of the spreading agent include, in addition tothe surface active agents as noted above, polyoxyethyleee resin acid(ester), ligninsulfonate, abietylenic acid salt,dinaphthylmethanedisulfonate, paraffin, etc. The composition formulatedin the form of granules may be normally applied as such withoutdilution.

The biological data of the indazole compounds (I) as herbicides will beillustratively shown in the following Examples wherein the phytotoxicityto crop plants and the herbicidal activity on weeds were observedvisually as to the degree of germination as well as the growthinhibition andrrated with an index 0, 1, 2, 3, 4 or 5, in which thenumeral "0" indicates no material difference is seen in comparison withthe untreated plant and the numeral "5" indicates the completeinhibition or death of the test The compounds shown in Table 5 belowwere used for comparison.

                  TABLE 5                                                         ______________________________________                                        Com-                                                                          pound                                                                         No.   Chemical structure     Remarks                                          ______________________________________                                               ##STR16##             U.S. Pat. No. 4,059,434                          B                                                                                    ##STR17##             Commercially available fungcide "chloro-                                      nitrofen"                                        ______________________________________                                    

TEST EXAMPLE 1

Cylindrical plastic pots (diameter, 10 cm; height, 10 cm) were filledwith upland field soil, and the seeds of Japanese millet, oats, tallmorningglory and velvetleaf were sowed therein and covered with soil. Adesigned amount of the test compound formulated in an emulsifiableconcentrate according to Formulation Example 2 or 5 was diluted withwater, and the dilution was sprayed onto the soil surface by means of asmall hand sprayer at a spray volume of 10 liters per are. The testplants were further grown in a greenhouse for 20 days, and theherbicidal activity was examined. The results are shown in Table 6.

                  TABLE 6                                                         ______________________________________                                                   Herbicidal activity                                                                                Tall                                          Compound                                                                              Dosage   Japanese       morning-                                                                             Velvet-                                No.     (g/are)  millet   Oats  glory  leaf                                   ______________________________________                                        1       40       5        5     5      5                                      2       40       5        5     5      5                                      3       40       5        5     5      5                                      4       40       5        5     5      5                                      5       40       5        5     5      5                                      6       40       5        5     5      5                                      7       40       5        5     5      5                                      ______________________________________                                    

TEST EXAMPLE 2

Cylindrical plastic pots (diameter, 10 cm; height, 10 cm) were filledwith upland field soil, and the seeds of Japanese millet, oats, radishand velvetleaf were sowed therein and cultivated in a greenhouse for 10days. A designed amount of the test compound formulated in anemulsifiable concentrate according to Formulation Example 2 or 5 wasdiluted with water containing a spreading agent, and the dilution wassprayed over the foliage of the test plants by means of a small handsprayer at a spray volume of 10 liters per are. The test plants werefurther grown in the greenhouse for 20 days, and the herbicidal activitywas examined. The results are shown in Table 7.

                  TABLE 7                                                         ______________________________________                                                   Herbicidal activity                                                Compound                                                                              Dosage   Japanese                                                     No.     (g/are)  millet   Oats  Radish Velvetleaf                             ______________________________________                                        1       20       5        5     5      5                                      2       20       5        5     5      5                                      3       20       5        5     5      5                                      4       20       5        5     5      5                                      5       20       5        5     5      5                                      6       20       5        5     5      5                                      7       20       5        5     5      5                                      8       20       5        5     5      5                                      ______________________________________                                    

TEST EXAMPLE 3

Cylindrical plastic pots (diameter, 8 cm; height, 12 cm) were filledwith paddy field soil, and the seeds of barnyardgrass (Echinochloaoryzicola), broad-leaved weeds (i.e. common falsepimpernel, indiantoothcup, waterwort) and hardstem bulrush were sowed in 1 to 2 cm depth.Water was poured therein to make a flooded condition. Buds of arrowheadwere sowed in 1 to 2 cm depth, and the test plants were grown in agreenhouse. Six days (at that time weeds began to germinate) thereafter,a designed amount of the test compound formulated in an emulsifiableconcentrate according to Formulation Example 2 or 5 and diluted withwater (5 ml) was applied to the pots by perfusion. The test plants weregrown for further 20 days in the greenhouse, and the herbicidal activitywas examined. The results are shown in Table 8.

                  TABLE 8                                                         ______________________________________                                                   Herbicidal activity                                                                 Barn-   Broad-                                               Compound                                                                              Dosage   yard-   leaved Hardstem                                                                             Arrow-                                 No.     (g/are)  grass   weed   bulrush                                                                              head                                   ______________________________________                                        1       2.5      5       5      5      5                                      2       2.5      5       5      5      5                                      3       2.5      5       5      5      5                                      4       2.5      5       5      5      5                                      5       2.5      5       5      5      5                                      6       2.5      5       5      5      5                                      7       2.5      5       5      4      5                                      B       2.5      2       3      1      0                                      ______________________________________                                    

TEST EXAMPLE 4

Vats (33 cm×23 cm×11 cm) were filled with upland field soil, and theseeds of soybean, corn, velvetleaf, black nightshade, commonlambsquarters and redroot pigweed were sowed therein to 1 to 2 cm depth.A designed amount of the test compound formulated in an emulsifiableconcentrate according to Formulation Example 2 or 5 was diluted withwater, and the dilution was sprayed onto the soil surface by means of asmall hand sprayer at a spray volume of 10 liters per are. The testplants were further grown in a greenhouse for 20 days, and theherbicidal activity was examined. The results are shown in Table 9.

                  TABLE 9                                                         ______________________________________                                                Herbicidal activity                                                                                                 Red-                            Com-                             Black Common root                            pound Dosage  Soy-        Velvet-                                                                              night-                                                                              lambs- pig-                            No.   (g/are) bean   Corn leaf   shade quarters                                                                             weed                            ______________________________________                                        1     5       1      1    5      5     5      5                                     2.5     0      0    5      2     5      5                               4     5       --     --   5      5     5      5                                     2.5     0      0    5      5     5      5                               5     5       --     1    5      5     5      5                                     2.5     0      0    5      3     5      5                               6     5       --     1    5      5     5      5                                     2.5     1      1    5      5     5      5                               7     5       0      0    5      4     5      5                                     2.5     0      0    5      2     4      4                               B     5       0      0    1      1     1      1                                     2.5     0      0    0      0     0      0                               ______________________________________                                    

TEST EXAMPLE 5

Vats (33 cm×23 cm×11 cm) were filled with upland field soil, and theseeds of soybean, velvetleaf, black nightshade and redroot pigweed weresowed therein and cultivated for 18 days in a greenhouse. A designedamount of the test compound formulated in an emulsifiable concentrateaccording to Formulation Example 2 or 5 was diluted with watercontaining a spreading agent, and the dilution was sprayed over thefoliage of the test plants by means of a small hand sprayer at a sprayvolume of 5 liters per are. The test plants were further grown in thegreenhouse for 20 days, and the herbicidal activity was examined. At thetime of the application, the test plants were generally at the 1 to 4leaf stage and in 2 to 12 cm height, although growing stage of the testplants varied depending on their species. The results are shown in Table10.

                  TABLE 10                                                        ______________________________________                                                  Herbicidal activity                                                 Com-                            Black                                         pound  Dosage            Velvet-                                                                              night- Redroot                                No.    (g/are)  Soybean  leaf   shade  pigweed                                ______________________________________                                        1      0.1      1        5      5      5                                      2      0.1      1        5      5      5                                      3      0.1      1        5      5      5                                      4      0.1      1        5      5      5                                      5      0.1      1        5      5      5                                      6      0.1      1        5      5      5                                      7      0.1      1        5      5      5                                      8      0.1      1        4      5      5                                      A      0.1      0        0      0      0                                      B      0.1      0        0      0      0                                      ______________________________________                                    

TEST EXAMPLE 6

Wagner's pots (1/5000 are) were filled with paddy field soil, and theseeds of barnyardgrass (Echinochloa oryzicola), broad-leaved weeds (e.g.common falsepimpernel, indian toothcup, waterwort) and statoblast ofneedle spikerush were sowed in 1 to 2 cm depth. Water was poured thereinto make a flooded condition. Rice seedlings of the 4-leaf stage weretransplanted therein and grown in a greenhouse. Five days (at that timebarnyardgrass began to germinate) thereafter, a designed amount of thetest compound formulated in an emulsifiable concentrate according toFormulation Example 2 or 5 and diluted with water (10 ml) was applied tothe pots by perfusion, followed by addition of water thereto to make a 4cm depth. The test plants were grown for further 20 days in thegreenhouse, and the herbicidal activity was examined. Two consecutivedays after the treatment, water was leaked out in an amount of 3 cmdepth per day. The results are shown in Table 11.

                  TABLE 11                                                        ______________________________________                                                    Herbicidal activity                                                                         Barn- Broad-                                        Compound Dosage   Rice    yard- leaved Needle                                 No.      (g/are)  plant   grass weed   spikerush                              ______________________________________                                        1        0.08     0       5     5      4                                      2        0.08     0       5     5      --                                     3        0.08     0       --    5      5                                      4        0.08     0       5     5      5                                      5        0.08     0       5     5      4                                      6        0.08     0       5     5      4                                      7        0.08     0       5     5      4                                      A        0.08     0       0     2      0                                      B        0.08     0       0     0      0                                      ______________________________________                                    

What is claimed is:
 1. A compound of the formula: ##STR18## wherein R isa C₁ -C₅ alkyl group, a C₃ -C₄ alkenyl group, a C₃ -C₄ alkynyl group ora C₁ -C₃ alkoxy(C₁ -C₂)alkyl group and B is --NHNH₂ or ##STR19##